A Bangladeshi diplomat is to leave his post in the Pakistani capital of Islamabad on January 7 after being expelled with "no explanation" by Pakistan, according to Bangladeshi officials.

Pakistani officials declared Maushumi Rahman, political counsellor at the Bangladeshi high commission in Islamabad, persona non grata as diplomatic tensions continue to rise between the two countries. The row has also seen a Pakistani diplomat accused of spying and expelled from the Bangladeshi capital, Dhaka.

"There was no explanation from Islamabad," Shahriar Alam, Bangladesh's junior foreign minister, told Reuters. "They could not cite any valid reason when they asked the Bangladesh High Commission to send back the counsellor."

When contacted by Reuters, Pakistani officials would not confirm that Rahman had been asked to leave the country.

The row was sparked in November 2015, following the executions in Bangladesh of two opposition leaders convicted of crimes against humanity during the 1971 war to break away from Pakistan.

Pakistan's foreign ministry expressed concerns about the trials of those involved in alleged atrocities during the war, saying they were "flawed".

In December, Pakistan withdrew Farina Arshad, a diplomat from its high commission in Dhaka, after Bangladeshi authorities accused her of spying and involvement in financing Islamist organizations. Pakistan said Arshad was withdrawn after "constantly being harassed by the Bangladeshi authorities".